TAP RULE

[jeff owens]

don't ask me why, but an engineer designed and had installed a remote indication for emergency power vs commercial by tapping the line side of an ATS switch with a 30 amp disconnect fused at 10 amps to supply a relay. we are relocating the ATS 30 feet away and they have incorporated into the design moving that disconnect to the new location leaving the relay/enclosure in the original location which they interpret from article 240.21(B) (1) that the TAP rule does not allow for the disconnect to be over 10 ft away.. I am in the process of getting approval to redesign the circuit to get the indication from an auxiliary contact instead of tapping the line side of the switch but am curious how this is kosher. shouldn't the disconnect be located 25 feet or less from the relay or at least in sight? the fused disconnect is protecting the relay, not the ATS. me thinks the interpretation is backwards. I read the code 240.21 (B) (4) (4)to apply here??

 

[charlie b]

Perhaps I am not understanding your description. But it seems to me that you are not dealing with a tap rule situation at all. You have a 10 amp fuse that is protecting the wires to the relay. I suspect that the wires have an ampacity of at least 10 amps. This is not a tap. An example of a tap would be if you start with a 100 amp breaker and feeders that have an ampacity of 100 amps, and you want to attach a feeder with an ampacity of 30 amps to the 100 amp feeder. If you include an overcurrent device rated at 30 amps at the point of connection, you don't have a tap. If you put the 30 amp overcurrent device not at the point of connection, but rather at a point 10 feet away, then you have 10 feet of 30 amp wire with a 100 amp overcurrent device ahead of it. That is a tap.

Can you clarify your installation?

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